Previously Untreated Childhood Rhabdomyosarcoma
Table 5. Radiation Therapy (RT) Dose According to Rhabdomyosarcoma Group, Histology, and Site of Disease (Children's Oncology Group [COG]) continued...
Chemotherapy Treatment Options
All children with rhabdomyosarcoma should receive chemotherapy. The intensity and duration of the chemotherapy are dependent on the Risk Group assignment. See Table 4 in the Stage Information section for more information about Risk Groups.
Adolescents treated with therapy for rhabdomyosarcoma experience less hematologic toxicity and more peripheral nerve toxicity than do younger patients.
Standard treatment options
- Low-risk patients have localized (nonmetastatic) embryonal histology tumors in favorable sites that have been grossly resected (Groups I and II), embryonal tumors in the orbit that have not been completely resected (Group III), and localized tumors in an unfavorable site that have been grossly resected (Groups I and II). (See Table 3 in the Stage Information section of this summary.) Certain subgroups of low-risk patients have achieved survival rates higher than 90% when treated with a two-drug chemotherapy regimen that includes vincristine and dactinomycin (VA) plus RT for residual tumor. See Table 6 below.
Table 6. Characteristics of Low-Risk Patients with High Survival Rates Using Two-Drug Therapy with Vincristine and Dactinomycin With or Without Radiation Therapy (Subset A)
|N0 = absence of nodal spread.|
|Orbital||Any||I, II, III||N0|
The COG-D9602 study stratified 388 patients with low-risk embryonal rhabdomyosarcoma into two groups. Treatment for subgroup A patients (n = 264; Stage 1 Group I/IIA, Stage 2 Group I, and Stage 1 Group III orbit) consisted of VA with or without RT for 48 weeks. Patients with subgroup B disease (n = 78; Stage 1 Group IIB/C, Stage I Group III nonorbit, Stage 2 Group II, and Stage 3 Group I/II disease) received VAC (total cumulative dose of 28.6 g/m2). Radiation doses were reduced from 41.4 Gy to 36 Gy for Stage 1 Group IIA patients and from 50 Gy or 59 Gy to 45 Gy for Group III orbit patients. For subgroup A patients, the 5-year overall FFS rate was 88% and the OS rate was 97%. For subgroup B patients, the 5-year FFS rate was 85% and the OS rate was 93%.
Other subgroups of low-risk patients have achieved survival rates of at least 90% with three-drug chemotherapy with VAC (total cyclophosphamide dose of 28.6 g/m2) plus RT for residual tumor. See Table 7 below.